Rotary and impact tool



`Fam. 26, 1954 Filed NOV. 2l, 1949 HI.; "J1 50 S. EVANS ROTARY ANDIMPACT TOOL l 2 Sheets-Sheet l Sei/7 Evans INVENTOR.

Way-KM AroRNEY Jan. 26, 1954 5 EVANS ROTARY AND IMPACT TOOL.

2 sheets-sheet 2 -Filed Nov. 21, 1949 1N V EN TOR.

ATTORNEY Patented Jan. 26, 1954 ROTARY n AND IMPACT TOOL Seth Evans,Houston, Tex., assignor to Hughes Tool Company, Houston, Tex., acorporation of Delaware Application November 21, 1949, Serial No.128,654

15 Claims.

This invention relates to an impact tool and more particularly to afluid actuated device especially adapted to use in forming earth boressuch as oil and gas wells by the rotary method of drilling.

While the description of the invention hereinafter is directed primarilyto the drilling of wells, it is to be understood that the invention isnot confined thereto, but may be used wherever energy is desired in theform of impacts to accomplish a given purpose.

When drilling wells by the rotary method of drilling, a bit is securedto the lower end of a tubular drill string. While this drill string andbit are rotated, with the bit on bottom, fluid is pumped downwardlythrough the drill string and out through the bit to eiect coolingthereof and to carry the cuttings removed from bottom upwardly withinthe well bore. Frequently, pressures of many thousands of pounds areapplied to the bit to induce cutting action upon bottom and,particularly Where earth strata are inclined, there is a tendency forthe well bore to deviate from the vertical. Furthermore, great dicultyis experienced in drilling in some extremely hard formations, such aschert and the rate or drilling in such formations is extremely slow.

It is a primary object of the invention to facilitate drilling and toovercome difficulties as above indicated and others that are experiencedwhen using conventional apparatus and techniques.

Another object oi the invention is to provide a device capable ofimparting impact energy to a rotary earth boring drill so that combinedaction of rotation and impact will effect drilling.

Another object is to provide an impact tool that will produce impacts ata rapid rate so that arelatively large amount of energy may be suppliedfor action, but Without excessive energy per stroke.

It is also an object to provide an impact tool having a wide range inlength of stroke whereby the tool may be readily maintained in operathigposition.

Still anotherobject is to provide a tool in which the range of pressureiluctuation is small whereby loss of energy and destructive effects uponequipment are minimized.

The invention also comprehends the provision of a combination rotary andimpact tool capable of drilling a straight hole, or of straighteninghole theretofore produced and deviating from the vertical.

l Still another object is to provide, in one form of the invention, animpact tool having a piston actuated by pressure fluid pumped downwardlyto the tool and cooperating means ior intermittent admission or pressurefluid to the piston and intervening isolation of the piston from thepumped fluid so that the return stroke of the piston is unaffected bythe fluid pumped during the period of isolation.

A still further object is to provide means for successively admittingpumped uid to the operating piston and isolating the piston from thefluid being pumped and means for storing energy for the succeedingstroke during the period of isolation.

The foregoing objects, together with other objects and advantages of theinvention, will be more fully apparent from the following descriptionconsidered in connection with the accompanying drawings in which:

Fig. 1 is an elevational View, partly in section, showing one form ofthe invention;

Fig. 2 is an elevational view, partly in section,

showing the accumulator used in connection with the structure shown inFig. 1 and comprising an upward continuation thereof;

Fig. 3 is a detail showing one form oi the valve structure of thedevice, parts being shown in their relative positions at the beginningof the downward stroke of the impact assembly;

Fig. 4 is a view similar to that shown in Fig. 3, but shows the relativeposition of parts when the impactassembly is in its lower-most position;

Fig. 5 is a detail sectional view showing alternate form of piston andvalve actuating mechanism;

Fig. 6 is a detail showing a still different form of the piston andvalve actuating mechanism.

A form of the invention is shown in Figs. l and 2 as comprising a body lhaving a cone type of bit 2 attached to the lower end thereof. The

body l is threaded internally at 3 for engagement with complementarythreads on the lower end of a drill string, or the threads 4 of theaccumulator, when used, shown generally at E andv opening to receive thebarrel i4 having passage l5 so that a stream of pumped fluid may passdownwardly into the chamber I5 and thence through the flushing passagesin the bit 2.

Attention is directed to the fact that the barrel Ill ts slidably withinthe spider II and has collar I5 secured thereto and resting upon anannulus II of resilient material, it being intended that this structureshall be capable of resisting shock and at the same time providing afluidE seall between the barrel and the spider.

A valve ts slidably within the body I and the lower end thereof isprovided with a seating;

surface 2l adapted to engage the complementary valve seat 22 on theinterior of the body. Similar'- ly, the upper end of the valve 2ilh'as avalvesurface 23 adapted to engage the complementary seat 24 on thenether side of the spider I I. The valve is shown in engagement withthis seat. in Fig. 4 and when in such position, passage I3 is closed toflow of iluid downwardly therethrough.

Slidably mounted within the body I and below the valve seat 22, is anannular piston. 25.- having inward projection 25 near its lower end,there being a seal between this projectionandthebarrel I4 to preventleakage of fiuid past thepistonat this point. It is apparent that thepiston 25 thusforrns the bottom of an annular piston cham-- ber I9.

The piston 25 terminates at its upper end in c. plurality of leaf springelements 2l, each being bifurcated at its upper end to receive valveactuating roller 28 mounted on pin 29 passing through thesebifurcations. The rollers 28 are adaptedto ride upon the inwardlyconverging surfaces 35 and 3| on the inwardly extending ribs 32 on thevalve 20. As the piston assembly moves downwardly from the positionshown in Fig. 3 and as the rollers 28 pass over the crest formed by thesurfaces 30 and 3i, the valve 20, under the iniiuence of leaf springs2l, is caused to move upwardly so that it will. engage the valve seat26, whereupon the piston 2G is isolated from fluid being pumpeddownwardly through the drill string and in the direction indicated bythe arrows 52 in Figs. 1 and 2.

As above indicated, closure ofthe valve 2Il'upon its seat 2l! terminatesilow of iiuid through the passage I3 so that continued. flow ismaintained only through thev barrel I4. Quite obviously, this conditiontends to produce pulsations in the hydraulic system. To minimize thiscondition and to store energy proximate the device to be used in asucceeding stroke, I provide the-accumulator 5 which, as aboveexplained, comprises body-extension 5 threaded at 4 and I forconnection, re-Y spectively, to the body I and the drill pipe with whichthe device is used. The annular piston within the extension 5 fitsslidably within thering 36 mounted in the extension proximate breatheropenings 3l. These openings permit liquidto freely ow to and from thespace 38 above the piston 35.

The piston 352carries a ring 33 engaged byonel or more compressionsprings shown as 40, 4I- having their opposite ends in abutment withcollar 42 secured in the extension 5 by suitable means such as the snapretainerring 43. A protective sleeve or liner 44 is secured to thecollar l2 and extends downwardly therefrom to confine the movement ofsprings 4U and 4I to the annular space 45 between such seeve and theextension It is to be noted that the piston 25has a downwardly facingshoulder [l5 which engagesy the upper end of a compression. spring 4l.;Theopposite. end. of'v this spring: is in engagement.. with disk;or'Bellevillaspring dlunderlying a shoulder:

49 on the interior of the body I. The disk spring is held in placeagainst the shoulder 49 by collar 50 threadably secured in the lower endof the body I. The lower end of the disk spring 48 is engageable by thearcuate shoulder 5I on the piston 25 whereby the assembly just describedis resiliently decelerated and brought to rest at an upwardlimit oftravel asl will be" more fully described. hereafter.

The piston 25 has inwardly extending projections 55 which move in closecontiguity with the outer surface of the barrel I4. These projectionsare capable of engaging the ring 56, reciprocable for. a limiteddistance on the surface of the barrel I4, andwhich is held in anuppermost position by the spring 57i' having its lower end in abutmentwith thering. 53 resting on an upwardly facing shoulder on the barrel.This arrangement serves asa. bumper for the piston 25 in event the toolis held in a suniciently elevated position that the piston 25 tendstomove downwardly beyondthe pointof. engagement of the projections 55withthe ring 55.

There is a splinedconnection 52. between. the piston 25 and the body Iso that reciprocatory movement may be had therebetween, but at the sametime, rotary driving actionby the bodywill be imparted to the piston andthe bit 2 secured thereto. This enables rotation of the bit inl thevmanner well-known in the rotary method, of drilling.

In further explaining. the operation of the device, thus far described,it will be noted that thev spring l'i normally holds the piston 25 in anuppermost position with the, shoulder 5I on the piston inengagementwith` the disk spring'd. Thevalve 25 is then in its lowermost position;shown.

in each of Figs. land 3 and fluid pumped downwardly, as indicated by thearrow 5.2,4 will exert pressure upon, and eiect downward movement of,

the piston 25. This will causey the bit 2 to ad. Vance and effect adesired impact upon the surface to be disintegrated. It is understood,ofy

course, that rotative effort will simultaneously be applied to the drillstem, to which the device4 is attachedso that cutting action from bothrotation and impact will be effected.

As the piston 25approaches its lowermost position the rollers. 25, rideover the crests formed at the meeting of converging surfaces 30 and 3.I.on the respectivev ribs 32 on the valve 29 whereby an upward componentof force is exerted on the valve which then moves upwardly so that theseating surface 23 on the valve, engages the. seat 24 whereby theadmission of fluid to the piston.25 is cut-off.

The movement of the valve upwardly uncovers ports 53 in the body I andsuch ports serve as exhaust openings for the fluid from above the piston25 as itv moves upwardly toward its uppermost position under theinfluence of thel spring lll. It is` to be understood. that, prior tothe initiation of the return movement of the piston. 25, the desiredimpact of the bit 2. on bottoinhas taken place.

As the piston 25 rises, the rollers 28 initially ride upon the surface3I- and thence upon the surfaces 3D, whereby a downward force is exertedon the valve 2B which moves the valve' downwardly, closes the ports 53and thereafter engages the seat 22, whereupon the component parts ofthe, assembly are in the initially assumed position o1'. Fig. 3.

The influx of fluid above the piston 25;- effects deceleration. of.`the;y piston and` associated parts of the piston-and-bit assembly andthe upward movementl of the piston is finally terminated by engagementof the shoulder 5I with the disk spring 48. This spring absorbs kineticenergy from the piston and thus prevents shock that would otherwiseresult. Also, the energy absorbed by the disk spring is returned to thepiston assembly as the succeeding downward stroke, above explained, isinitiated.

It is also to be understood that when the accumulator 5 is used, thepiston 35 thereof moves upwardly after the valve 29 engages the seat2-4, and in this manner energy is restored in the spring or springs, i8and il so that luiddisplacement will subsequently take place fromdownward movement of the piston 35 to transfer the stored energy to thepiston on the succeeding downward stroke of the latter.

An important feature of the invention resides in the fact that thedevice is capable of effecting a relatively large range of length ofstrokes. In devices in accordance with the invention, it has been foundthat stroke lengths from one and one-fourth inch to two and one-fourthinches can be had and are extremely effective. For such a range ofstroke lengths, the splined connection 52 should be in the neighborhoodof two and one-half inches, and for such illustrative dimension, thetool should be so held that the bit is between one and one-fourth inchand two and one-fourth inches, maximum, off bottom during drilling. Thisrange of oif-bottom distance enables ease of control in lowering thetool and drill string at the proper rate to obtain most effectivecutting action.

In the form of the piston and valve mechanism shown in Fig. 5, thepiston is shown at 25 and has paired upstanding ears 60 to receive pivotpin 6i upon which bell-crank 62 is adapted to rock. This bell-cranklever is bifurcated at its upper end and carries the roller 23 upon pin29 so that the roller rides upon the rib 32' on the valve 20. The rib 32on the valve is slightly modied from that previously described in thatthe inwardly converging surfaces and 3l merge into a ilat inner surfaceE3. This feature causes a slight delay in the movement of the valve froma given terminal position and hence provides a somewhat greater strokeof the piston.

The bell-crank lever E2 is constantly urged in a clockwise direction bya collar 64 slidably surrounding the barrel Ell and pressed upwardly bythe spring 65, having its lower end resting upon the shoulder $5 on theinner periphery of the piston.

The port 53' for the exhaust of uid from above the piston 25', when thevalve 2D is in its uppermost position, communicates with a passage 61 inthe wall of the body I, and this passage preferably terminates inwardlybelow the seal 26 so that the exhausted fluids pass downwardly throughthe conventional ushing passages in the bit 2 to clean and cool thecutters thereon and also to impinge upon the bottom of the hole and thusassist in disintegration of the bottom.

In the modiiication shown in Fig. 6, the valve 20" has inwardlyextending webs 'l0 which carry an integral sleeve 'il on their innerends. This sleeve has ribs 32, each of which is engaged by a roller 28carried by a bell-crank lever 62 mounted on a pin di carried by thepiston 25" which has an annular groove 12 to receive springs 'i3 whichconstantly urge] the actuator rings I4 upwardly, whereby the bell-cranklevers 62' are urged in a counter-clockwise direction and the rollers 28are held in engagement with the ribs 32". This form also utilizes aspring 'I which engages a shoulder 15 on the barrel I4 and the lower endof the sleeve 1I. The compressive force exerted by this springsupplements the upward component of force exerted on the valve 2U by therollers 28 riding upon the surfaces 3|" of the ribs 32".

Broadly, the invention comprehends a fluid actuated impact tool capableof effecting both rotary and impact action to disintegrate earthformations and to thereby form bore holes in the earth.

The invention claimed is:

1. An impact device comprising, a body adapted to be attached to thelower end of a drill pipe and having at least one port between theinterior and exterior thereof, a baiile in said body above said portforming an annular passage axially of the body, a piston mounted toreciprocate within the body and forming the bottom of a chamber belowsaid baille, an annular valve slidably mounted in the body and movableto alternately close said port and said passage, whereby pumped iluid isintermittently directed to and from said chamber.

2. An impact device comprising, a body adapted to be attached to thelower vend of a drill pipe and having at least one port between theinterior and exterior thereof, a baiile extending transversely of thebody above said port and forming an annular passage within the body andabove the port, a piston mounted to reciprocate within the body belowsaid bafe thereby forming a chamber in the body above the piston, avalve seat on said baiiie, a second valve seat within the body belowsaid port, and an annular valve slid-v ably mounted in the body andmovable to alternately engage said seats to open and closel said passageand said port so that fluid pumped into the body is intermittentlydirected to and from said chamber.

3. An impact device comprising, a body adapted to be attached to thelower end o-f a drill pipe and having at least one port between theinterior and exterior thereof, a baffle extending transversely of thebody above said port and forming an annular passage within the body, abarrel secured in said bailie and extending downwardly, said barrelproviding a iiuid by-pass from above the baffle to a point therebelowand forming, with the body, an annular chamber, an annular pistonmounted to reciprocate within and forming the bottom of said chamber,and an annular valve slidably mounted in the body and movable toalternately 'close and open said passage and port respectively so thatfluid pumped into the body is intermittently directed to and from saidchamber.

4. An impact device comprising, a body, adapted to be attached to thelower end of a drill pipe, a piston in said lbody, a valve seat withinthe body, a valve movable to and from said seat, said valve includingopposed camming surfaces thereon, and means carried by the piston andengageable with said camming surfaces for moving said valve to and fromsaid seat so that pumped iluid is alternately applied to and dischargedfrom above the piston.

5. In a iiuid operated impact tool wherein a piston is normallyresiliently urged upwardly within the tool body counter to the directionof movement of actuating pressure fluid the improvement comprising,means for alternately adademas mitting: pressure fluid to; the pistoniand isolating the pistonfromthe pressure fluid, means for exhaustingfluid from above the piston during the periods` of isolation, andadditional means for storing pressure fluid` energy supplied during theperiods of isolation.

6. An impact tool comprising a body, a piston therein, resilient meansnormally biasing said piston to an uppermost position, means foralternately admitting pressure fluid to and from the chamber abovethe'piston, and additional means for resilient engagement by the pistonat the end of'itsupward stroke tov absorb energy therefrom andthereafter accelerate the piston in a downward direction at thebeginning'of the succeeding downward stroke.

7. An impact tool comprising a body, a piston therein, means forproducing reciprocatory movement of the piston from fluid pumped,downwardly into the body, and means for decelerating the pistonproximate the end of. its upward stroke and thereafter accelerating thepiston at the beginning of the succeeding downward stroke.

8. An impact tool comprising a body, a piston therein, means forproducing reciprocatory movement of the piston from fluid pumpeddownwardly into the body, means for decelerating the piston proximatethe end of its upward stroke and thereafter accelerating the piston atthe beginning of the succeeding downward stroke, said last mentionedmeans comprising a disk spring mounted within the body, and an abutmenton the pistonv engageable thereby.

9. 1n combination, a fluid actuated impact device, including a pistonand means for intermittently admitting fluid to and exhausting fluidfrom above the piston, and an accumulator connected to said impactdevice to absorb energy from the uid stream, during the period thepiston rises for a succeeding stroke.

10. In combination, a fluid actuatedv impact device including, a pistonand means for successively admitting fluid ilow to the pist-on andisolating the piston from the fluid flow, and an accumulator connectedto the impact device to absorb energy from the fluid stream during theperiod the piston rises for a succeeding stroke.

11. A device of the class described comprising, a body adapted to beattached to the lower end of a drill pipe, a piston therein, means forsuccessively admitting uid flow to and isolating the piston from fluidow downwardly through the drill pipe, an upward extension on said body,and means in said extension for successively absorbing and releasingenergy of the fluid stream to minimize pulsations in the stream as saidfirst mentioned means successively isolates and admits fluid flow to thepiston.

l2. A device of the class described comprising, a body adapted to beattached to the lower end of a drill pipe, a piston therein, means forsuccessively admitting fluid ow to andl isolating the piston from fluidflow downwardly through the drill pipe, an upward extension on saidbody. and means in said extension for successively absorbing andreleasing energy of the fluid stream to minimize pulsations in thestream, said last mentioned means including an annular piston having itsopposite sides subjected respectively to the fluid pressures interiorlyand exterorly of the body.

13. In a device of the class described, a body, a piston reciprocabletherein, spaced Valve seats within the body, a valve slidable axially ofthe body to alternately engage said seats, converging surfaces on saidvalve and extending longitudinally thereof, and a spring pressed elementcarried by the pist-on and riding upon said surfaces so that the valveis urged from seat to seat as the element rides alternately upon saidsurfaces.

111. In aV device of the class described, a body, a piston reciprocabletherein, spaced valve seats within the body, a valve slidable axially ofthe body to alternately engage said seats, radially extending ribs onsaid valve, converging surfaces on the free edge of each of said ribs,and means carried by the piston to alternately apply a resilientpressure upon said surfaces so that the valve is urged from seat toseat.

15. An impact device comprising, a body adapted to be attached to thelower end of a drill pipe and having at least one port between theinterior and exterior thereof, a baille extendingl transversely of thebody above said port and'forming an annular passage within the body andabove the port, a piston mounted to reciprocate within thev body belowsaid baffle thereby forming a chamber in the body above the piston, avalve seat on said baille, a second valve seat within the body belowsaid port, an annular Valve slidably mounted in the body and movable toalternately engage said seats to open and close said passage and saidport so that fluid pumped into the body is intermittently directed toand from said chamber, and means forming a fluid by-pass from above thebaille to a point therebelow to by-passy a portion of the pumped fluid.

SETH EVANS.

References Cited in the le 0f this patent UNITED STATES PATENTS NumberName Date 910,447 Bant et al 1 Jan. 19, 1909 1,087,632 Benjamin Feb. 17,1914 1,132,063 Bordeen Mar. 16, 1915 1,892,517 Pennington Dec. 27, 19322,359,147 Mertenr Sept. 26, 1944 2,390,646 Hays Dec. 11, 1945 2,422,031Merten June 10, 1947 2,424,108 Merten July 15, 1947 2,507,585 BassingerMay 16, 1950

